Unfortunately ice doesn't work this way in 1.3.1, so only items like evertide amulet would be a good source of water, but it will probably be a problem in about a month. I wonder what EE3 will bring on the table, because currently I treat EE2 only as a source of OP items, using transmutation table / energy condenser to make non EE items just takes fun away from using other mods.
Back to the topic, I think that obsidian generator is very natural use of RP2 pumps. I made one while breading bees in the nether (with extra bees there is quite a lot of them), but based on double row of water, extended pistons below, and then row of lava. The only issue I have with RP pipes, is that they can pump lava from 50 meters below. It just feel weird. RP2 has quite realistic feeling, with small more magical/minecrafty elements, but nothing in grates and pipes doesn't look like it would allow for pumping things from such distance below. I'd say 3 blocks for lava and 9 blocks for water should be maximum height of the pump above water source (after pump it could go on any height, maybe using simplified model with proportional energy usage/efficiency to pipe length and destination height). In buildcraft pump pipe looks more advanced, so it could have pumps along the way. Maybe I'm just picky, but it is really bothering me. I even added recipes for smelting dusts to blast furnace via railcraft api. Making iron from iron ore in electric furnace without coal is magical, it can heat steak, not reduce iron oxide.
Edit: jppk1 Like I was saying, you can use EE without using transmutation table. It is still OP, but also fun.